The use of a vibrating elevator with a helical ramp is well known in the art for the purpose of raising granular, extruded or pellet products. Such an apparatus also makes it possible to bring about the separation of the granular products on the one hand from larger products rising within the granulated product layer and on the other hand from smaller products coming directly into contact with the ramp.
Such an apparatus can be simultaneously used as a heat exchanger. French patent application 2634187 consequently describes an apparatus having a vibrating helical coil, so that heat takes place by indirect contact with a heat transfer fluid immersing the turns of the coil or by direct contact with at least one gas flowing within the coil in cocurrent or countercurrent manner with respect to the flow direction of the solid particles.